ICEM struct mesh diverges, ANSYS unstruct does not
 

Hi all,




I am trying to simulate a jet impingement on a flat plate (single jet).


BC for the simulations:

• Inlet - Mass flow
• Jet walls - wall
• Outlet - Pressure outlet
• TargetPlate - Wall, with const. heat flux - 1000 w/(m^2)

Initially, I meshed the geometry with ansys meshing tool - from the workbench. This was an unstructured mesh. The simulation produced satisfactory results without divergence.



Then, I tried to simulate for the same geometry, using a structured mesh - using ICEM CFD. The BCs were same as that of the unstruct mesh.



Observations for the simulation using ICEM mesh:-

• The file from icem is imported to fluent without any errors.
• But, when running the simulations, right from the first step, there is an error message displaying: "Temperature has been limited to 5e+03K in zone .. and 1.00e+00K in zone.." - which corresponds to the exit and inlet respectively
• When viewing the diverged contour, there was high temp contours near the jetwalls - I honestly cannot understand why this happened.

Thinking that I made an error in struct meshing, I tried simulations with new meshes - I improved the mesh quality to 0.7; still no result.





Then I tried the same case for a square duct - still the same error.




I humbly ask of you to help me figure out the problem -- I have been struck with this error for 2 weeks :'(




Thank you so much guys!

Still not working for a geometry from icem cfd tutorial manual
 

Hello,


So I created a structured mesh using icem for one of the geometries specified in the tutorial. I followed whatever steps they had mentioned, exactly.



I ran a simulation for this geometry, with similar bcs mentioned in the main post.



I am still getting the message: 'Temperature limited to 5e+03K on zones...'



Can someone please give me pointers on where I might be going wrong?


Thanks.

I think the problem is in fluent not in ICEM. So I would consult the Fluent forum. Probably it is something numerical.

As a start I would set the limits in fluent to realistic values. Depending on the problem you are solving: minimum 273 K and max 500 K?

Okay. I will try posting this on the fluent forum.



Yes, I will try limiting the temperature values.


Thank you!